Diarrhea can result from a variety of physiological disorders including bacterial and parasitic infections, disease or debilitation of organs such as liver, adrenal and others. It can also occur as a result of other therapy or diet. In all cases, diarrhea is generally a symptom of organic gastrointestinal disorders and not itself a disorder. Chronic diarrhea is generally due to intestinal hypermotility and rapid transport. It may also be due to, or accompanied by hypersecretion of acid gastric juices or decreased reabsorption and may, in some instances, particularly those accompanied by hypersecretion, be associated with emotional tension and psychological conflicts. Therapeutic compositions administered in accordance with the present invention relieve diarrheal symptoms. Antidiarrheal compounds are, of course, well-known in the medicinal arts and take various forms. In particular there are a variety of products known which act systemically to provide antidiarrheal effects when administered in a manner which will enable the drug to be taken into the system at effective therapeutic levels. For example, U.S. Pat. No. 4,060,635 discloses a class of amidinourea derivatives with systemic antidiarrheal effects. Generally, however, compounds such as the amidinoureas exhibit their antidiarrheal properties only at dose levels which produce other significant side effects. The amidinoureas for example are also known to exhibit local anesthetic and antiarrhythmic effects as disclosed in a copending application by J. Diamond and G. Douglas, Ser. No. 671,762. It has recently been found that when such amidinoureas are treated with a derivatizing agent there is produced a cyclic derivative which has been characterized as a substituted 1,2-dihydro-1,3,5-triazin-2-one. It has now been found that when the cyclic derivatives are administered to animals in accordance with test protocols that have been established to mimic gastrointestinal disorders these compounds produce effects which can be correlated to therapeutically useful effects in the treatment of human patients for diarrhea and related gastrointestinal disorders. These compounds have been found to have a regulating effect on such disorders when produced in experimental models. In general, systemic antidiarrheal products have a therapeutic index such that effective antidiarrheal doses cannot be attained without significant side effects. It is an object of the present invention to provide a systemic antidiarrheal composition which can be administered at dosage levels that significantly inhibit or suppress the symptoms of diarrhea without other significant pharmacologic effects.